I am looking at getting some small VFD's to run a couple of bench lathes (3/4 to 1-1/2HP), and also a couple of industrial sewing machines.
who makes a good, low priced one? are there any of any price range still made here in the USA, or at least not in china?
I don't think any of the major brand VFDs being sold here in the US are made in "China" yet, at least not the entire thing. But many are made in Taiwan, and they are very good products. Most are made in Asia somewhere; Korea, Malaysia, Singapore, Taiwan, a few in Japan still. The only mfr I know of left in the US for small HP drives is AC Tech, and I'm not sure if their newest ones are still made here or elsewhere now. A-B still makes their larger drives in the US, but the small ones are all brand-labeled from Asian suppliers. ABB makes their larger drives for the US market in the US (Milwuakee area) but even for them, I think the small ones are Asian. Toshiba used to have a VFD assembly plant in Texas, I hear they shut it down recently.
i was looking at these, mostly because they are cheap:
http://dealerselectric.com/item.asp?cID=&PID=999
does anyone have any experience with these in terms of quality, and are there any particular VFD's that one should avoid all together?
The GE drives are actually Fuji, a Japanese company, probably made in Malaysia. That's kind of the way things are now with small cheap drives; American company name, Japanese or European engineering, cheap Asian labor for assembly. Good drives though, nothing wrong with them. But understand that Dealers Electric is a surplus house, so most of their product is NOS (New Old Stock) from someone else, not necessarily the manufacturer (unless they are dumping old product when a new line comes out). Some people don't care and like the pricing, but recognize that they are not experts on the drives they sell, they are brokers. If you want support, buy from official distributors who are required to have trained people on staff as part of their dealership.
also, I was wondering if VFD's that can run off of 115V single ø like this GE one I linked to need de-rating for HP/amperage when running off of the lower voltage and outputting 208 3ø?
Most VFDs 5 HP and under will accept 1 phase in and give you 3 phase out without de-rating.
Several (if not most) also offer versions like this that have a "voltage doubler" in them which allows you to give it 120V single phase in, 240V 3 phase out up to about 1HP max. The Dealer's Electric web page description doesn't make that clear, but that's the way it works. You can always program a VFD to limit the voltage to anything less than it's rating, i.e. 208V instead of 230V, that is inherent in the design.
I personally like the Teco drives. For your applications I think you would like the EV Series; inexpensive, very easy to program, good quality. A lot of people who frequent this site like them too. Others like the Hitachi J Series, nothing wrong with that drive either.
